These antibody studies are designed to develop improved methods for detecting and treating malignancies. Our group performs preclinical evaluation of radiolabeled antibodies that appear to be promising after initial screening. The clinical trials evaluating their pharmacokinetics and dosimetry are performed by our group. One collaborative radioimmunotherapy trial with Dr. Waldmann (PI), in which we used humanized anti-tac monoclonal antibody,in patients with non ATL lymphomas is ongoing and with responses seen in numerours patients. Dr. Paik has focused his chemistry work including markers of angiogenesis. Various protocols using [F-18] FDG in PET and [O-15] water for tumor detection, followup, and blood flow measurements are ongoing with NCI. We continue work using FDG as a surrogate marker of resposne and disease status in a variety of malignacy. We continue to build on prior studies and are utilizing fluorodeoxyglucose PET in attemps to localize sites of activated lymphomcytes. We continue to evaluate the ability of FDG-PET to differentiate between patients with benign versus lymphomatous adenopathy in the setting of autoimmune lymphoprolifertive syndrome versus. We are collaborating within the Imaging science program and NIAID in evalauting new tracer to evaluate the pathogenesis of HIV infection in vitro.